US2110405A - Fluid metering and distributing system - Google Patents

Description

March s, 1938. A, M TARR 2,110,405

FLUID METERING AND DISTRIBUTING SYSTEM Filed March 23, 1936 2 Sheets-Sheet l J2 I Z/ t..

March s, 1938. A. M. STARR FLUID METERING DISTRIBUTING SYSTEM Filed March 25, 1936 2 Sheets-Sheet 2 mu -n mH-mn -H -H mH-lmw wil wwm 9 mxv m V P W w 1 mm QM w 7 N: W N W RN NM i Q i am m Q g INVENTOR. 4//a/7 M 3727/?" Patented Mar. 8, 1938 PATENT OFFICE rum) METERING SYS AND DISTRIBUTING TEM Allan M. Starr, Piedmont, Calif., assignor, by

mesne assignments,

to Starr & Sweetland, a

co-partnership composed of Ernest J. Sweetland and Allan M. Starr, as co-partners, Piedmont, Calif.

Application March 23, 1936, Serial No. 70,338

2 Claims.

This invention relates to means for metering and distributing fuel to the cylinders of internal combustion engines and is particularly designed for use in engines of the fuel injection type.

An object of my invention is to provide a metering and distributing unit which is simple in construction and positive in operation. Fuel for internal combustion engines of the fuel injection type is customarily delivered to the injector nozl (or intake manifold) thereof at very high pressure which may be 1,000 pounds per square inch or more in certain cases. When fuel oil is handled under such high pressure it is desirable to make the distance between the distributor element and the metering element as short as possible because where these elements are separated by any considerable distance and connected by tubular conduits, the results are influenced by inertia of fuel 0 within the conduits, by the slight compressibility of fuel, and by various other factors. By the construction employed in my invention I entirely eliminate. lengthy conduits between the 25 distributor and metering elements and assemble is capable of accurate metering and distribution at very high speeds but eliminates many of the objections found in metering and distributing systems heretofore devised, aswill be understood by reference to the drawings.

The invention possesses other advantageous features, some of which with the foregoing, will be set forth in the' following description where the forms of the invention which have been selected for illustration in the drawings accompanying and forming a part of the present specification are outlined in full. However, I do not confine my invention to the specific forms'set forth in the drawings and specification nor to the specific uses of the invention herein set forth, as it is capable of manymodifications which are limited only by' the scope of the appended claims.

Referring to the drawings:

Figure 1 diagrammatically represents a plan view of a four cylinder engine wherein mydistributing and metering system is employed.

Figure 2 shows an exterior plan view of the invention.

Figure 3 is a side elevation of the device shown in Figure 2 together with an eccentric means of controlling the amount of fuel metered at each charge. I

Figure 4 is a vertical sectional elevation taken on the lines 44 of Figure 2.

zles in the cylinders or combustion chambers the units in a single compact block which not only Figure 5 is a horizontal section taken on the lines 55 of Figure 4.

Figures 6, 8, 10, and 12 are vertical sections taken on the line 6t ol2 of Figure 2.

Figure 7 is a horizontal section on the line 1--'I of Figure 6.

Figure 9 is a horizontal section on the line 9-9 of Figure 8.

Figure 11 is a horizontal section onthe line l ll| of Figure 10.

Figure 13 is a horizontal section. on the line l3l3 of Figure 12.

Briefly the invention consistsfof a housing in which is mounted a rotary valve plug and a. metering chamber containing a metering piston. An adjustable stop is provided to control the length of stroke of the metering piston. 'This' piston is an accurately ground fit in the metering chamber, dividing it into two sections and the displacement caused by the reciprocating movement of the piston governs the size of each. fuel charge. The rotary valve serves the purpose of admitting fuel under high pressure, first to one end of the metering chamber and then the other, thus causing the piston to reciprocate. The fuel entering one end of the chamber forces the piston to the opposite end and expels the charge of fuel therefrom; then when the valve reverses the flow of fuel and admits it to the end of the chamber that has just been emptied, the piston returns to its former position, forcing the fuel charge out of the end just filled. The size of the fuel charge is governed by the length of stroke of the metering piston which, in turn, is governed by the position of the adjustable stop. The valve plug which alternately admits fuel to opposite ends of the metering chamber serves the additional purpose of distributing the fuel to conduits leading to the injector nozzles in the engine cylinders. is accomplished by a series of ports and conduits in the valve plug and housing as will be understood by reference to the drawings and the following description.

The object of Figures 6 to 13 inclusive is to indicate by the arrows thereon the direction of flow of the fuel at various positions assumed by the moving parts of the device during its cycle of operations. The drawings and description in this application illustrate the use of my invention in connection with a four cylinder internal combustion engine but the same principle may be applied for metering and distributing fuel to any number of cylinders as Will be understood by those skilled in the art.

Referring to Figure 1, the numeral 5 represents the metering and distributing apparatus as a whole, represents a cylinder block of an engine and la, 2a, 3a., and 4a are injector nozzles of any approved type, preferably the spring-loaded type, which inject into the cylinder only when receiving fuel at a pressure suflicient to overcome the spring tension which normally holds a valve in the nozzle in closed position. I b, 2b, 3b, and 4b represent conduits which are for the purpose of delivering fuel from the apparatus 5 to the engine cylinders Ix, 2x, 3x, and 4:: respectively; it being understood thatthe' present description applies to a 4 cycle engine and that the firing order in this instance is 1, 2, 4, 3. 6 is a fuel pump which delivers the fuel under pressure into a pressure tank or accumulator i from the fuel storage tank 8.

to a throttle lever or governor by any convenient In Figure 2, I2 is the head of a screw which forms a closure for the metering chamber and i3 is a rod which is a ground fit through the center of the screw l2 and is used for the purpose of regulating the stroke of the metering plunger as will be'explained in detail further on. i4 is the top of the rotatable distributing element, or valve plug, which is securely held against longitudinal movement 'by the slotted member l5 which is held in place by the screw l6, it being understood that the slot in the part l5 allows suflicient clearance to permit the free rotation of the element H. The numerals 2, 3, and 4 in Figure 2 designate the outlets of the distributor casing which are connected by the conduits lb, 2b, 3b, and 4b to the cylinders Is, 23:, 3x, and 4:2.

Each of the outlets I, 2, 3, and 4 is connected by a lateral conduit to the central aperture of the casing block asindicated by the dotted lines lo, 20, 3c, and 40, it being understood that the conduit 20 connects to the central aperture,

through a radial branch conduit in the same vertical plane as conduit |c but at' a lower level, and

that the conduit 40 connects with the central aperture through a radial conduit directly below the conduit 30. i1 is the fuel inlet which brings the supply of fuel under pressure from the acshown with the lower end of the central rotatable plug membei' l4 extending through the housing. The lower end of i4 is provided with a slot extending to the line it. The purpose of the slot I3 is to receive a drive shaft which is geared to the engine in such manner as to cause the element l4 -to make one revolutionfor each two revolutions of the 'crank shaft of the enginein the case of a 4-cycle engine. The screw 2| forms a closure for the lower end of the metering chamber and the upper end of this screw is ground flat to form a stop for the metering plunger as is indicated at 2|a in Figure 6. It will be noted that the upper end of screw 2| is reduced in diameter to provide an annular space forming a part of chamber 32. This annular space is of such size as to make the cubic contents of chambers 32 and 32a substantially equal under, average run-' ning conditions, whereby compressibility of fuel has the sameeffect in both chambers and therefore does notadversely affect metering. m -Figs ure 3 the rod 3 which limits the travel of the .tric 22 (Figure 3).

means (not shown).

The sectional view Figure 4 which is taken on the line 4-4 of Figure 2, shows the casing lo, the central rotating element l4 and certain of the conduits for the distribution of fuel. This view which cuts through the conduits and 3 shows the radial conduits lo and 30 bymeans of which the openings and 3 connect with the cen trai aperture; and the conduits 2c and 4c con necting openings 2 and 4 with the'central apertureat' a lower level. The valve plug |4 which is an accurately ground fit in the central aperture of the block I is provided with circumferential grooves 24 and 25. The groove 24 is in open communication with the conduit 26 which alternately connects the groove 24 with conduits 3c and le during the rotation of the valve plug. Also communicating with the groove 24 are a pair of oppositely disposed longitudinal grooves, one of which is shown at 21. These grooves during rotation of the valve plug |4 alternately communicate with conduit ||a (see Fig. 2) which is the inlet for fuel under pressure into the spaces within the valve plug.

The valve plug |4 contains another pair of iongitudinal grooves or slots 28 and 28a. These are set at right angles to the grooves 21 and 21a and are in open communication with the circumferential groove 25. It should be noted that the length of the grooves 21, 21a, 28 and 28a is such that they overlap at the line -5 of Figure 4 so that in the rotation of the valve plug |4 each of these longitudinal slots in turn gets into communication with the fuel inlet opening ||a (see Fig. 2) whereby the fluid pressure in Ila is alternately, and at 90 intervals,.connected with peripheral grooves 24 and 25.

The angular passageway 29 is in open communication with the peripheral groove 25 so that during the rotation of the plug |4 the peripheral groove 25 is alternately brought into communication with the conduits 2c and 40 which lead to injector nozzles. The functions of the parts shown in Figures 2 and 4' will be more clearly understood by reference to the succeeding figures and description. v

Figure 5 which is a horizontal section on the line 5-4 of Figure 4 shows the position of the ducts or slots 21, 21a, 28, 28a and certain of the conduits through the housing It. This view also shows the metering piston 3| in section and it should be understood that this plunger is an 'accurately ground fit in the casing so'as to prevent leakage of fuel between the metering piston and the walls enclosing it. Piston 3| is sometimes referredito as'a movable partition.

Figure 6 shows the metering plunger 3| during its upstroke. In this and the succeeding views the eccentric 22 which limits the outward travel of rod I3 is omitted; but it will be understood that the pressure of fuel within the metering chamber constantly urges the rod ll outwardly and thereby keeps it firmly bearing against the eccen- From the description thus far it will be understood that the metering and glistributing apparatus consists of a casing .lll having a central aperture, which is-an accurately ground, flt to receive the valve plug.| 4;,,this plug is caused to rotate at the rate of onerevolution for each two revolutions of the 4 cycle engine crank shaft; and that thevalve plug and easing form a closely ground and lapped fit to prevent leakage or-passage of fuel except through the ports provided for that purpose. Also, that since the metering piston 3| is also a lapped and ground fit in the metering chamber, the plunger 3| will reciprocate back and forth between the face 2la and the lower end of the rod l3 in accordance with the differential in fuel pressure in the respective metering chambers which are designated'by the numerals 32 and 32a. It is therefore obvious that if the pump 6 and accumulator I constantly maintain a high fluid pressure through the conduit Na, and this fluid pressure isalternately connected with chambers 32 and 32a by means of ports in the rotating valve plug I4; that the metering plunger 3| will be caused to reciprocate back and forth with each alternation of pressure at the respective ends of the piston 3|; and also that the length of travel of the piston 3|, and consequently the amount of fuel admitted at each stroke, will be governed by the position of the rod l3 which in turn is regulated by the eccentric 22. And further, that each stroke of the piston 3| forces the metered fuel out of one of the chambers 32 or 320. at the end of the piston, and that the fuel thus forced out is led in turn to an engine cylinder in accordance with the firing order of these cylinders, as will be understood by a study of the succeeding figures and following description.

The arrows in the conduits in Figure 6 and Figure 7 indicate that the pressure of fuel has entered through the conduit Ha, has been admitted through the port 28 into the groove 25 from which it passes directly through the pas-, sageway 33 into the chamber 32 and forces the piston 3| to its upward position, driving the fuel out of the chamber 32a through the passageway 34 into the groove 24 and thence outwardly through the conduit 26 which in this position of the valve plug is in registration with conduit lc, which leads to the pipe lb and nozzle l-a into cylinder la: of the engine.

Referring to Figures 8 and 9, the valve plug l4 has advanced 90 from the position shown in Figure 6 and in this position represents the fuel under pressure entering through conduit Ha.-

passing through port 21a into the groove 24 which places it in direct communication with the chamber 320. through conduit 34, forcing the piston 3i downwardly, and thus forcing a metered charge of fuel through the conduit 33 into the groove 25 and out through conduit 29 which at this point is in registration with conduit 20 whence the fuel is forced through the conduit 2b and injector nozzle 2a into the cylinder 22: of the engine.

In Figures 10 and 11 the valve plug l4 has advanced another 90 and in this position the fuel has entered through conduit Ila into the port 280, and groove 25 which has led it directly into chamber 32 forcing the piston 3| upwardly to discharge the fuel out of chamber 32a into groove 24, thence through the conduit 26 which at this point is in registration with conduit 30 to lead the fuel through conduit 4b and injector nozzle 4a. into cylinder 4m.

The next advance of 90' of the-valve plug l4 carries it back to the position illustrated in Fig- I ing piston that slides back and forth between the chambers 32 and 32a, it is within the province of my invention to supplant the piston 3| with any device such as a diaphragm which in effect serves I the purpose of a movable partition, the movement of which is controlled to vary the displacement of fuel affected within chambers 32 and 32a.

While I have illustrated and described my metering and distributing system in connection with injector nozzles which are assumed to be mounted in the cylinders or combustion chambers of internal combustion engines, the device-1s equally applicable for use in cases where it may be desired to inject the fuel, whether volatile or otherwise, into any desired part of the intake manifold of an engine.

My apparatus may be used inconnection with 2-cycle engines if desired by' changing the rate of rotation of the valve and other changes that will be obvious to those skilled in the art.

The ports or passageways in the valve mechanism may be referred to as inlet ports or inlet passageways; or outlet ports or outlet passageways according to whether they admit fluid to the metering chambers or provide exit therefrom. V

I claim:

1.'A mechanism for metering a fluid comprising a casing having a pair of substantially parallel chambers of circular cross section, a metering piston slidably mounted in one of said chambers and a closure at each end thereof; means for controlling the stroke of said piston; a rotary valve plug in the other of said chambers; a pair of transverse conduits connecting said parallel chambers adjacent each end of said slidably mounted piston; a pair of circumferential grooves in said rotary valve plug, each one in communication with one of said transverse conduits; a feed conduit leading through said casing and communicating with said valve plug; a plurality of feed ducts in said valve plug'certain of which ducts communicate with one of said circumfercumferential grooves; said feed ducts having communication with said feed conduit during the rotation of said valve plug; said ducts being alternately disposed so that each of said circumferential grooves is alternately. brought into communication with said feed conduit during. the rotation of said plug; a plurality of fluid outlet ports in said casing; passageways through said valve plug communicating with each circumferential groove and each communicating with an outlet port. during each rotation ofsaid valve plug; pump means to force a fluid through said feed conduit and associated passageways.

2. Means for metering fluids comprising a casential grooves while the other ducts intermediate f thereof communicate with the other of said ciring; a cylindrical bore through said casing; a valve plug rotatably mountedinsaid bore; a pair of circumferential grooves in said plug; a feed conduit through said casing terminating in a feed port intermediate of said circumferential grooves; a plurality of slots'in said valve plug ea'ch having intermittent communication with said feed port and with one of saidgrooves, alternate slots communicating with the upper groove and intermediate slots communicating with the lower groove; a secondary cylindrical bore in said casing; a piston in said secondary bore; adjustable means to govern the stroke of said piston; a metering chamber at each end 'of said piston; a

conduit-leading from one of said chambers to the first mentioned bore to communicate with the upper circumferential groove and a conduit leading from the other chamber to thelower circumferential groove; a plurality oi outlet ports intermittently communicating with said circumferential grooves; ,said ports being placed to open said upper groove is in registry with said feed port.

. ALLAN M. STARR.

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